|
| |
|
|
A020453
|
|
Primes that contain digits 1 and 5 only.
|
|
1
| |
|
|
5, 11, 151, 1151, 1511, 11551, 15511, 15551, 51151, 51511, 51551, 55511, 115151, 511111, 511151, 515111, 1111151, 1115551, 1155151, 1551551, 1555111, 5115511, 5151151, 5151551, 5155511, 5511151, 5511511, 5515151, 5551111, 15511151
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| The first 8 terms are also primes when read backward, i.e. in A007500. See also A199325. - M. F. Hasler, Nov 05 2011
|
|
|
PROG
| (PARI) {L=[1, 5]; for(d=1, 9, u=vector(d, i, 10^(d-i))~; forvec(v=vector(d, i, [1, #L]), ispseudoprime(t=vector(d, i, L[v[i]])*u)&print1(t", ")))} \\ - M. F. Hasler, Nov 05 2011
|
|
|
CROSSREFS
| Sequence in context: A094108 A197538 A083418 * A036932 A162252 A179388
Adjacent sequences: A020450 A020451 A020452 * A020454 A020455 A020456
|
|
|
KEYWORD
| nonn,base
|
|
|
AUTHOR
| David W. Wilson (davidwwilson(AT)comcast.net)
|
| |
|
|
